Juice lawn grass?

The objections I have read are:
1. cant digest cellulose
;;;I am not eating the whole plant, plus I probably could use a bit more fiber in my diet.
2. Wild things poop.
;;; I also eat other things like herbs and lettuce that are subject to said poop. There is a spot that I can pick grass that I am certain the birds don't hang out, namely a under leaning concrete wall that my cat sleeps on.
3. Spray ;;; I have a reel mower and I never spray my lawn
4. Oxolic acid
;;;This is what concerns me, I am not fond of the supposed side effects of this stuff. But it does not taste like other things that are high in oxolic acid. In the chalky mouth feel way.
5.Deadly mold
;;;again, I eath other "normal" greens that would be subject to the evils of nature. Plus I dusted my property with safe mycorrhizae
6.Dogs pee there
;;; I don't own a dog, and I am not aware of any feral dogs here. Plus I doubt a small amount would cause any harm.
7. Chemtrails!
;;; Again everything I eat would be subject to that.

Also I tried a glass worth, and it had a refreshing, not unpleasant taste and my gut gave no complaints.
Any other thoughts of what I should consider?

Sounds like the risk (cyanide in non-native varieties) even as low as it is, isn't really worth it since the grass is so low in food value. (See link) That said if you can verify species, juicing may be a way to add extra chlorophyll to your diet. I wouldn't worry about oxalic acid, or any poo/pee residue if you give it a quick rinse.
http://www.eattheweeds.com/can-we-eat-grass/

I have juiced grass to experiment with the liquid as a fertilizer. I've not consumed it. I found the flavor unappealing.

Wheat grass is another story. Blending the juice from wheatgrass with juices from other plants produces a tasty drink. I picked up Stainless Steel Wheat Grass Hand Juicer a couple of years ago and started to experiment with it. I found that much more than 25% wheatgrass juice gave me the runs and I moved on to other projects.